The present invention relates to drip irrigation emitters and to drip irrigation lines of the type including a continuous tube having a plurality of emitters spaced longitudinally along its length.
Drip irrigation lines of the foregoing type are gaining widespread use because of their efficiency in the delivery of irrigating water directly to the plant roots, and their substantial savings in the irrigation water required. Such drip irrigation lines generally comprise a tube having a plurality of discharge ports spaced along its length, and a flow-reducer emitters fixed to the tube at each of the discharge ports. In the flow-regulated irrigation line, each of the emitter includes a rigid plastic member and an elastomeric member fixed to the rigid plastic member and therewith a flow-reducing passageway communicating with its respective discharge port, which passageway is automatically enlarged or restricted by the deformation of the elastomeric member in response to flow.
The elastomeric member, in the conventional emitter, is usually in the form of a planar diaphragm, and the rigid plastic member is usually formed with embossments cooperable with the planar diaphragm to define the enlargeable/restrictable flow-reducing passageway regulating the flow to the discharge port. Such a construction has been found to have a number of drawbacks to be referred to below.